1. Field of the Invention
This invention relates to a polysilane composition suitable for use, for example, as a third-order non-linear optical material and to a non-linear optical device employing the polysilane composition.
2. Description of Related Art
Polysilanes are organic polymers whose main chain is of Si--Si structure, wherein the side chains usually have hydrophobic groups such as alkyl groups or aryl groups. Due to delocalization of the .sigma. electrons of the Si--Si bonds, these polymers have photosensitivity, semiconducting characteristics, non-linear optical characteristics, and the like. In particular, the .sigma.-conjugate system of the Si--Si main chain of the polysilane is transparent to light in the visible region, which is very promising in regard to application in the field of optoelectronics.
A non-linear optical device making use of the non-linear optical effect of polysilane is disclosed in Japanese Patent Publication No. 1-183420. However, the third-order non-linear optical constant .chi..sup.(3) of polysilane is not particularly great, being about 10.sup.-12 esu, while values less than about 10.sup.-10 ; generally from about 10.sup.-10 to about 10.sup.-5 esu are generally necessary in an optical application. It has not therefore proved possible to obtain optical output of sufficient intensity simply by non-linear polarization of polysilane.